19 research outputs found

    Buried Pre-Illinoian-Age Lacustrine Deposits with “Green Rust” Colors in Clermont County, Ohio

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    Author Institution: Bennett & Williams Environmental Consultants Inc., Columbus, OHAuthor Institution: The Ohio State University, School of Environment and Natural Resources, Columbus, OHBuried, Pre-Illinoian-age lacustrine deposits found in at least two separate bedrock valleys in Clermont County, OH, exhibit brilliant colors of “green rust” that alter rapidly when exposed to oxygen. In these settings, the materials are leached of calcium carbonate but the iron has not undergone the redoximorphic depletion typically observed in gleyed hydric soils. Water movement has been exclusively through fractures and along varved bedding planes for approximately 700,000 years, indicating that in these settings, matrix flow is not occurring. The overlying Pre-Illinoian-age Backbone Creek glacial till also exhibits gleyed coloration but these materials are not leached of calcium carbonate. These materials also oxidize when exposed to air, indicating that again, the iron is not removed from the till. A possible correlation to similar permeability properties in northwest Ohio Late-Wisconsinan-age lacustrine materials and fine-grained tills is drawn. The “green rust” provides evidence for minimal to no matrix flow in fine-grained materials and supports the Ohio Fracture Flow Working Group recommendation that water movement along fractures, varved bedding planes, through sand stringers, and along paleosol unconformities be assumed unless matrix contributions have been documented and can be confirmed in these settings

    La mineralogía de la arcilla del suelo Nipe

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    The mineralogy of Nipe clay was characterized by means of X-ray diffraction (XRD), differential scanning calorimetry (DSC), infrared spectroscopy (FTIR), BET surface area, and chemical analysts. The major components of the clay fraction are goethite, gibbsite, hematite and kaolinite. Goethite is the predominant iron oxide as indicated by the high intensity of the XRD peaks. The unit cell dimensions of goethite, estimated from the XRD data, were a = 4.603 Å, b = 9.806 Å and c = 3.002 Å. The unit cell dimensions of hematite were a = 5.037 Å, and c = 13.735 Å. The extent of aluminum substitution in goethite and hematite was also estimated from the XRD data. The mole % Al in goethite, based on the d (111) value, was 15.57 mole percent, whereas when the a-dimension of the unit cell was used, a value of 12.86 mole percent was obtained. The estimated mole percent Al substitution in hematite was 0.67. The hematite/goethite ratio as estimated from the relative intensities of the 104 peak of hematite and the 110 peak of goethite was 0.51. Kaolinite showed a high capacity to absorb IR radiation as indicated by strong absorption peaks around 1000 and 3700 cm-1. The surface area of the clay as determined by the BET method was 55.26 m2/g. The ratio of Feox/Fed was very low (1.17x10-2), indicating that the iron oxides occur in well crystallized form.La mineralogía de la arcilla del suelo Nipe se caracterizó usando difracción de rayos X, análisis termal, espectroscopia de infrarojo, área superficial (BET) y análisis químico. Los principales componentes minerales de la arcilla son goetita, gibsita, hematita y caolinita. La intensidad de los picos correspondientes a goetita, revelada mediante el análisis de rayos X, indica que este mineral es el óxido de Fe predominante en la arcilla del suelo Nipe. Los parámetros estructurales de la celda unitaria de goetita, estimados del análisis de rayos X, fueron a = 4.603 Å, b = 9.806 Å, y c = 3.002 Å. Los parámetros estructurales de hematita fueron: a = 5.037 Å y c = 13.735 Å. De los datos de rayos X también se estimó el porcentaje molar de aluminio en goetita y hematita. Para el caso particular de la goetita, el porcentaje de Al se estimó a base del la distancia interplanar d(111) y a base del tamaño de la unidad estructural-a de la celda unitaria, obteniéndose valores de 15.57 y 12.86%, respectivamente, El porcentaje de aluminio en la hematita fue de 0.67%, y se estimó a base del tamaño de la unidad estructural-a de la celda unitaria. Se obtuvo una proporción de hematita/goetita de 0.51. La caolinita demostró gran capacidad para absorber la radiación infrarroja según lo indican los picos de absorción en la cercanía de los 1000 y 3700 cm-1. El área de superficie de la arcilla fue de 55.26 m2/g. El contenido de óxidos amorfos fue muy bajo (Feox/Fed = 1.17x 10-2), lo que indica que los óxidos de hierro están mayormente en forma cristalina

    Effects of Phosphate Fertilizer Applications and Chemistry-Mineralogy of the Iron Oxide System on Phosphate Adsorption-Desorption by Stream Sediments : Final Report

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    (print) vii, 102 p. : ill., maps ; 28 cm.Item lacks publication date. Issue date supplied from WorldCat bibliographic recordDespite geologic, geomorphic, and land use differences, suspended sediments collected from the Muskingum River and its tributaries during spring flooding were remarkably uniform in mineralogy and size distribution. The greatest evidence of regional differences came from Moxahala Creek, which receives acid drainage from abandoned coal mines. As a result, Black Fork Creek, a tributary to Moxahala Creek, was chosen for detailed water quality and bottom sediment studies. Marked increases in dissolved SO4, Fe, and Al, and decreased. pH were observed in sections of the stream affected by acid mine drainage. In addition, a gelatinous yellow precipitate of iron was abundant in the bottom sediments below sources of pollution. This Fe-oxide or oxyhydroxide precipitate greatly increased surface area and reactivity of bottom sediments and added to the overall sediment load. A standard P adsorption procedure was proposed and the ability of four laboratories to produce consistent results over a wide range of soils was determined. Soil (0.5 or 1.0 g) was shaken in 0.01 mol L-1 CaCl2 at a soil: solution ratio of 1:25 in containers allowing a 50% head space for 24 hours at 24 to 26°C on an end-over-end shaker. Initial dissolved inorganic P concentrations of 0 to 323 u mol P L-1 (as KH2PO4 or NaH2PO4) were used and microbial activity inhibited by 20 g L-1 chloroform. Excellent agreement between the four laboratories was obtained for P adsorbed by the 12 soils studied, with a mean coefficient of variation over all P levels and soils of 0.91%. The laboratories also exhibited a high degree of replication of individual treatments with no laboratory showing a strong consistent bias across all soils and P levels in terms of P adsorption. Langmuir, Freundlich and Tempkin adsorption models were highly correlated with the adsorption data. Respective mean correlations for the 12 soils were 0.98, 0.97 and 0.95. The proposed method has the potential to produce consistent results which can be used to predict partitioning of dissolved inorganic P between solid and solution phases in the environment.Acknowledgements -- Abstract -- Chapter 1: Suspended Sediments of the Muskingum River Basin -- Chapter 2: Water and Bottom Sediment Quality in Streams Affected by Acid Coal Mine Drainage - a Study of the Black Fork Creek Watershed, Ohio -- Chapter 3: Interlaboratory Comparison of a Standardized Phosphorus Adsorption Procedur

    Properties of the Fractured Glacial Till at the Madison County, Ohio, Field Workshop Pit Site

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    Author Institution: USDA/ARS, Soil Drainage Research Unit ; School of Natural Resources, The Ohio State University ; Department of Food, Agricultural and Biological Engineering, The Ohio State UniversityWater and contaminants obviously do move through the so-called impermeable glacial tills in Ohio. This study was conducted to illustrate the extensive presence of fractures in the till and to quantify the differences in hydraulic conductivity and physical and chemical properties between the fractureaffected zones and the till matrix. In situ measurements of the saturated hydraulic conductivity were made in small boreholes positioned either in the matrix or intersecting the fractures. Soil samples from both the fracture faces and the matrix were analyzed for particle size distribution, clay mineralogy, calcite, dolomite, and iron content. Hydraulic conductivity measured in boreholes intersecting fractures was 1.25 x 105 cm/sec (0.018 in/hr), one order of magnitude greater than in boreholes in the matrix. Particle size distribution was the same for the fracture faces and the matrix. The fracture faces showed no significant change in total clay content and a slight increase in expandable clay. Calcite content was 62% greater, dolomite content was 6% lower, and iron content was 73% lower on the fracture faces as compared to the matrix. The fractures affected approximately 7% of the soil volume

    2019 International Consensus on Cardiopulmonary Resuscitation and Emergency Cardiovascular Care Science With Treatment Recommendations

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    The International Liaison Committee on Resuscitation has initiated a continuous review of new, peer-reviewed, published cardiopulmonary resuscitation science. This is the third annual summary of the International Liaison Committee on Resuscitation International Consensus on Cardiopulmonary Resuscitation and Emergency Cardiovascular Care Science With Treatment Recommendations. It addresses the most recent published resuscitation evidence reviewed by International Liaison Committee on Resuscitation Task Force science experts. This summary addresses the role of cardiac arrest centers and dispatcher-assisted cardiopulmonary resuscitation, the role of extracorporeal cardiopulmonary resuscitation in adults and children, vasopressors in adults, advanced airway interventions in adults and children, targeted temperature management in children after cardiac arrest, initial oxygen concentration during resuscitation of newborns, and interventions for presyncope by first aid providers. Members from 6 International Liaison Committee on Resuscitation task forces have assessed, discussed, and debated the certainty of the evidence on the basis of the Grading of Recommendations, Assessment, Development, and Evaluation criteria, and their statements include consensus treatment recommendations. Insights into the deliberations of the task forces are provided in the Justification and Evidence to Decision Framework Highlights sections. The task forces also listed priority knowledge gaps for further research

    Oxidation of isochemical FeS2 (marcasite-pyrite) by Acidithiobacillus thiooxidans and Acidithiobacillus ferrooxidans

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    A research-grade mineral sample that contained marcasite and pyrite (FeS2) was subjected to the oxidation by Acidithiobacillus ferrooxidans and Acidithiobacillus thiooxidans. Oxidation of FeS2 by A. ferrooxidans produced acid, and the redox potential increased with sulfide dissolution and the oxidation of Fe2+. jarosite was detected in solids from spent cultures. Preferential oxidation of either mineral was not consistently observed across all treatments. Neither iron sulfide was oxidized by A. thiooxidans. (C) 2006 Elsevier Ltd. All rights reserved
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